<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>


  <script>
    let a=1;
    console.log(1)


    var obj={};
    obj.id="123";
    delete obj.id
    obj.name="yyyy";

    console.log(obj.id+obj.name)
  </script>
</head>
<body>

</body>
</html>